688 Identification of biomarkers of early innate events during skin reaction following intradermal injection

Abstract

trifluoro-1-isopropyl-2-oxopropyl]aminocarbonyl] pyrrolidin-1-yl] carbonyl]-2-methylpropyl]aminocarbonyl]benzoylamino]acetate (NEI-L1) was approved as a quasi-drug ingredient to improve wrinkles in 2016 in Japan. The product containing NEI-L1 has been used by many Japanese women in the past two years. NEI-L1 has the strong effect to inhibit the activity of neutrophil elastase (NE). Neutrophils are migrated into dermis by stimuli such as ultraviolet irradiation and they release NE to degrade dermal extracellular matrix (ECM). NEI-L1 suppresses degradation of ECM and improves the wrinkle. In this study, we examined whether NEI-L1 suppresses NE-induced collagen degradation using the culture supernatant of normal human dermal fibroblasts in vitro experiment and cultured human skin tissues ex vivo experiment. As a result of in vitro experiment, collagen content in supernatant treated with 2.5 mg/mL NE was significantly reduced (4.6%) compared to non-treated control. On the other hand, 10 mg/mL NEI-L1 drastically suppressed this